#18,928
Over the past 24-hours the tabloids and mainstream media have been filled with reports of a `new' coronavirus discovered in a Brazilian bat; one that shares an uncomfortably close genetic profile with both SARS-COV-2 and MERS-CoV.
While all of that makes for great clickable headlines, it is worth noting this `new' virus was actually detected in samples that were collected between May and August 2019 (months before COVID emerged), but have only recently been analyzed.
That doesn't mean this isn't a potential zoonotic threat, only that it has been around for some time without actually spilling over to humans; as have likely other similar coronaviruses, many yet to be discovered.
And indeed, since the original SARS-CoV outbreak in 2002-2003, we've seen similar viruses reported around the globe, including:
V. Sinica: Pangolin HKU4-related Coronaviruses Found in Greater Bamboo Bat From Southern China
Emerg. Microbes & Infect.: Novel Coronaviruses In Least Horseshoe Bats In Southwestern China
PNAS: SARS-like WIV1-CoV Poised For Human Emergence
While once only influenza A was thought likely to spark a global pandemic, COVID proved that coronaviruses can have the `right stuff' as well.
Which is why we continue to follow MERS-CoV reports closely, and we've seen calls for the development of `Pan-Coronavirus' vaccines, that could conceivably protect against a wider range of threats.What has caught the eye of many with this preprint is that this virus - dubbed BRZ batCoV - contains a furin cleavage site that is nearly identical to the one found in SARS-CoV-2; a motif that is credited with increasing COVID's host cell tropism and viral spread.
I've posted the link and abstract below, and the full PDF is available at this link.
I'll have a brief postscript after the break.
A divergent betacoronavirus with a functional furin cleavage site in South American batsKosuke Takada, Nicholas Yamahoki, Jonathon C. O. Mifsud, Itsuki Anzai, Tadashi Maemura, Francisco Borges Costa, Eric Takashi Kamakura de Carvalho Mesquita, Mateus de Souza Ribeiro Mioni, Tiago JS Lopes, Yoshihiro Kawaoka, Jane Megid, Edward C. Holmes, Tokiko Watanabe
doi: https://doi.org/10.1101/2025.10.24.684489
Abstract
Bats are natural reservoirs for a wide range of RNA viruses. Members of the genus Betacoronavirus, including Severe Acute Respiratory Syndrome virus 2 (SARS-CoV-2) and Middle East Respiratory Syndrome virus (MERS-CoV), have attracted particular attention due to their recent zoonotic emergence. However, much of the known diversity of betacoronaviruses is based on data from Asia, Africa, and the Middle East, with limited genomic information available from the Americas.
Herein, we report the complete genome of a novel bat betacoronavirus identified from a Pteronotus parnellii bat sampled in Brazil. Phylogenetic analysis revealed that this virus is sufficiently distinct from the five recognized Betacoronavirus subgenera to represent a new subgenus.
Of note, the spike protein of this novel bat coronavirus possesses a functional furin cleavage site at the S1/S2 junction with a unique amino acid sequence motif (RDAR) that differs from that found in SARS-CoV-2 (RRAR) by only one amino acid.
Comparative structural analysis identified other betacoronaviruses in bats with furin cleavage sites at the S1/S2 junction, suggesting that this region is a structurally permissive “hotspot” for cleavage site incorporation. Our study provides a broader understanding of the phylogenetic and functional diversity of bat coronaviruses as well as their zoonotic potential.
And when that day comes, we'll regret every day we squandered not aggressively preparing for its arrival.